Hopea rudiformis Ashton, d. Bull. Sing. 31 (1978)

Latin for 'roughly-shaped'?

Mid-canopy tree up to 36 m tall and 67 cm dbh. Stem with resin. Stipules dropped early. Leaves alternate, simple, penni-veined, conspicuous secondary veins. Flowers ca. 4 mm in diameter, white-yellow, placed in panicles. Fruits ca. 8 mm long, green, with rwo ca. 56 mm long wings, wind dispersed.

Medium-sized tree. Twigs, leaf buds and parts of petals exposed in bud densely +/- persistently pale tawny puberulent; panicles sparsely so; calyx outside and nerves and midrib beneath sparsely caducously so. Twigs c. 2 mm diameter apically, rather straight, ribbed, becoming smooth, dark brown. Bud small, ovoid, acute; stipules fugaceous, unknown. Leaves 6.5-14 by 3.5-7.5 cm, ovate to broadly lanceolate, thinly coriaceous, minutely stellate lepidote and appearing pale and dull beneath: margin subrevolute; base broadly cuneate; acumen to 1.5 cm long, broad, tapering, down curved and twisted over on pressing; nerves 11-13 pairs, slender but prominent beneath, +/- obscurely depressed above, arched, at 55 -65 degrees ; secondary nerves few, short, hardly elevated beneath; tertiary nerves densely scalariform, obscure; petiole 8-13 mm long. Panicle to 3.5 cm long, to 2-axillary; singly branched, branchlets bearing to 3 flowers; bracts unknown, fugaceous. Flower bud to 3 by 2 mm, ovoid, small. Sepals subequal, broadly ovate, subacuminate. Stamens 15, in 3 subequal verticels; filaments compressed at base, tapering medially and filiform below the shortly oblong anthers; appendages slightly longer than anthers, short, slender. Ovary ovoid, surmounted by an indistinct tapering ciliate stylopodium, and short columnar style c. half length of ovary and stylopodium. Fruit pedicel to 2 mm long, short, base of ripe fruit +/- impressed. 2 longer calyx lobes to 9 by 2 cm, broadly spatulate, obtuse, c. 3 mm broad above the to 6 by 5 mm ovate deeply saccate thickened base; 3 shorter lobes to 8 by 8 mm, ovate, chartaceous at margin, subacute, reaching apex of nut and adpressed to it; nut to 8 by 8 mm, ovoid, terminating in the persistently truncate stylopodium. [from Flora Malesiana]

In undisturbed mixed dipterocarp forests up to 200 m altitude. Usually growing on alluvial sites, but also present on hillsides. On sandy to clayey soils.

The timber is used.


Local names
Borneo: Damar batu, Damar jankar, Damar putih, Emang bakau, Putang lanan, Selangan jangkang.